Immunotherapy is known to be effective in late-stage, mismatch repair (MMR) deficient colorectal cancers but not in MMR proficient cancer. This study reports the early results from the NICHE clinical trial that is evaluating treatment of early stage, nonmetastatic preoperative colon cancer with a CTLA-4 inhibitor and a PD-1 inhibitor. Chalabi and colleagues report that the treatment was well tolerated and that a major pathological response was seen in 19/20 patients with MMR deficient tumors and 3/15 MMR proficient tumors. HALO image analysis software was used in this publication for analysis of T-cell biomarkers CD3, CD8, and FOXP3 on chromogenically stained tumor biopsies. First, image registration with HALO was performed of three serial tissue sections. Tissue sections were annotated manually, and quantification of DAB positivity was performed with the Multiplex IHC module and expressed as a function of tumor area. The authors conclude that immunotherapy shows promise to become the standard of care in a defined group of early-stage colon cancers.